tcp: don't clear retransmit_skb_hint when not necessary
Most importantly avoid doing it with cumulative ACK. Not clearing
means that we no longer need n^2 processing in resolution of each
fast recovery.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f900fae..239cea7 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -750,7 +750,7 @@
BUG_ON(len > skb->len);
- tcp_clear_all_retrans_hints(tp);
+ tcp_clear_retrans_hints_partial(tp);
nsize = skb_headlen(skb) - len;
if (nsize < 0)
nsize = 0;
@@ -1823,7 +1823,9 @@
tp->packets_out -= tcp_skb_pcount(next_skb);
/* changed transmit queue under us so clear hints */
- tcp_clear_all_retrans_hints(tp);
+ tcp_clear_retrans_hints_partial(tp);
+ if (next_skb == tp->retransmit_skb_hint)
+ tp->retransmit_skb_hint = skb;
sk_wmem_free_skb(sk, next_skb);
}
@@ -1853,7 +1855,7 @@
}
}
- tcp_clear_all_retrans_hints(tp);
+ tcp_clear_retrans_hints_partial(tp);
if (prior_lost == tp->lost_out)
return;